Replace apivore with rswag for api tests (#969)

* Replace apivore api tests with rswag
* move to OpenAPI Spec 3.0.1
* a swagger UI is now reachable at http://localhost:3000/api-docs/index.html
*  swagger file is generated by running  `RAILS_ENV=test rails rswag`
    and it was moved from /docs/swagger.v1.yml to /swagger/v1/swagger.yml

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Co-authored-by: viehlieb <pf@pragma-shift.net>

Gemfile

@@ -55,6 +55,9 @@ gem 'gaffe'
 gem 'ruby-filemagic'
 gem 'mime-types'
 gem 'midi-smtp-server'
+gem 'hashie', '~> 3.4.6', require: false # https://github.com/westfieldlabs/apivore/issues/114
+gem 'rswag-api'
+gem 'rswag-ui'
 
 # we use the git version of acts_as_versioned, and need to include it in this Gemfile
 gem 'acts_as_versioned', git: 'https://github.com/technoweenie/acts_as_versioned.git'
@@ -116,6 +119,5 @@ group :test do
   gem 'simplecov', require: false
   gem 'simplecov-lcov', require: false
   # api
-  gem 'apivore', require: false
-  gem 'hashie', '~> 3.4.6', require: false # https://github.com/westfieldlabs/apivore/issues/114
+  gem 'rswag-specs'
 end